The present invention relates to change-speed gearing units for automobiles, and more particularly to a lubrication mechanism in a change-speed gearing unit in which an oil transfer trough is suspended in a fore-and-aft direction at one side of the inner wall of an extension housing for the unit.
In general, such a conventional oil transfer trough as described above is made of pressed sheet metal and may have a number of manufacturing errors caused in the pressing process. To overcome such manufacturing errors, the oil transfer trough is attached in a tight manner to the side wall of the extension housing, causing undesired deformation of the trough. If the oil transfer trough is loosely attached to the inner wall of the extension housing to avoid such undesired deformation, undesired vibrations and unpleasant noises will occur. In application of the conventional oil transfer trough, it is also required to provide a lateral through hole in the side wall of the extension housing located at the rear end of the trough thereby to direct the flow of lubricating oil toward the interior space of the housing. The lateral through hole is formed by drilling the side wall of the extension housing and is closed by a plug element at its outer end. This increases the manufacturing cost of the lubrication mechanism.